I just finished putting a 1975 250ci Chevy 6 in my 54 6100. It bolted right up to the transmission. I cut the motor mount platforms out of the donor truck, held the motor in place and cut the platforms to fit, because the 54 frame is narrower, drilled holes and bolted them in. I haul 8000# of water with it every day and it has performed flawlessly for the past 2 months. The engine has a lot more power, has an easy to replace spin-on oil filter and the price was right. I paid $300 for the whole donor truck.
